The present invention relates generally to battery terminal clamping mechanisms, such as are known for securing associated and encircling legs of the terminal about an upwardly, generally conically, extending battery post. More particularly, the present invention discloses an improved clamping mechanism for securing, in a tightened position, the terminal legs about the post in a non-destructive fashion, and which further provides, in a loosened position, for controlled spring-back of the terminal legs from about the battery post.
The prior art is fairly well documented with numerous examples of battery terminal clamping mechanisms. As is known in the art, a suitable clamping mechanism is necessary in many battery terminal applications and in order to ensure the establishment of a continuous and electrically conductive communication between the battery and its associated terminal line.
Referring to FIG. 1 of the present drawing illustrations, entitled Prior Art, an illustration is provided at 2 of a conventional battery terminal and which is suitable for engaging such as a generally conical shaped post (see at 3 in FIG. 8), the post 3 in turn corresponding to either a positive or negative terminal of an associated battery (not shown). The terminal 2 is typically constructed of a suitable and copper stamped material, having a substantially elongated and flattened body and exhibiting the necessary properties of electrical conductivity and resiliency. The terminal 2 is also preferably tin plated and, in structure, terminates at one end in a pair of extending and bendable gripping tabs 4 which, upon being folded towards each other as shown in FIG. 8, grippingly secure an extending end of an associated terminal line 5.
The conventional terminal 2 further includes, at another end, a substantially annular shaped post fitting, defined by an upwardly and generally annular shaped wall 6 with an open interior. An inner annular surface 8 of the post fitting is preferably defined by a plurality of spaced apart serrations 8, one purpose for which being to provide a degree of anti-rotative engagement with the post 3 to which it is secured. A pair of spaced apart guide walls 10 and 12 define a slot therebetween, the slot facilitating actuation of the terminal between the tightened and loosened positions during both installation and removal from the battery post 3.
The terminal 2 further includes such features as a first leg, typically provided as a plate 14 and which is communicable with the first spaced apart guide wall 10 and terminates in an upwardly angled tab 16. A second extending leg (such as further defined by plate 18) is likewise communicable with the second spaced apart guide wall 12 and extends in substantially parallel spaced apart fashion (see also exploded view of FIG. 3) before terminating in a slightly forwardly extended position beyond the upwardly angled tab 16. A threaded post 20 extends upwardly from the second plate 18 proximate its forward terminating end.
Having described with sufficient detail the several features of the stamped terminal 2, reference is again made to a prior art clamping mechanism, illustrated in part by a slider mechanism 24 supported upon an upper surface of the second plate 18 and including a lengthwise extending slot 26 through which is received the upwardly angled tab 16 and to permit the slider mechanism 24 a range of laterally displaceable motion. The slider mechanism 24 defines an overall arcuate configuration and includes an enlarged rounded end, through which is formed a central, and somewhat elongated, aperture defined by tapered extending sides 28.
The clamping mechanism further includes a hex head nut 30 exhibiting a downwardly extending and tapered ledge 32 and which, upon being threadably engaged over the post 20, is tightened in a downward direction. Upon coming into contact with an uppermost location of the tapered extending sides 28 of the sliding mechanism aperture, continued rotation of the nut 30 in the tightening direction causes the tapered ledge 32 of the hex nut 30 to travel along the downward slope established by the tapered sides 28. This in turn causes the slider mechanism 28 to laterally displace in the direction of the second plate 18, in turn causing the angled tab 16 and associated first plate 14 to close in pincer fashion against the second plate 18.
Loosening of the slider mechanism 24 is accomplished by reverse rotation of the hex nut 30, thus causing a reverse travel of the associated tapered ledge 32 in a reverse and upwardly sloping direction along the tapered sides 28 of the slider mechanism aperture. Reference is also made to U.S. Pat. No. 5,879,202, issued to Zhao, and which discloses the battery terminal connector according to that as substantially described above.
While providing, at least initially, an effective clamping mechanism for use with a battery terminal, the terminal arrangement of FIG. 1 suffers from certain shortcomings arising primarily from the nature of the material properties of the terminal 2. These include the gradual inability of slider mechanism 24 to xe2x80x9cspring backxe2x80x9d to its loosened position following threaded disengagement of the hex nut 30.
Inadequate spring back of the terminal is further largely a result of plastic deformation (creep) of the metal in the terminal 2 after extended periods of time in the tightened position. As such, it has been found necessary to employ a secondary tool of some nature to forcibly pry open the associated legs (plates 14 and 18) of the terminal 2 and in order to achieve the desired spacing between the guide walls 10 and 12 to facilitate the removal of the terminal 2 from the battery post 3. The less than optimal desired degree of spring back additionally causes a permanent deformation on the terminal""s extruded diameter (in proximity of the connection between the post fitting and the associated plates 14 and 18), such that the fit of the terminal 2 about the battery post 3 is successively degraded.
Inadequate spring back in the stamped terminal (again as a symptom of plastic deformation of the terminal 2) also results from excessive clamping torque applied to the mechanism during the initial tightening stage. It has also been found that such excessive clamping torque also results in the inner annular and serrated surface 8 of the post fitting biting into the lead composition of the battery post 3, often causing damage to the post 3, an accumulation of such damage eventually leading to the non-usability of the battery. Accordingly, an evident shortcoming in the prior art is the provision of a clamping mechanism, which possesses the ability to maintain a measured degree of clamping and holding forces and, by avoiding over-torquing of the terminal, prevents plastic deformation of the terminal.
The present invention, as previously described, discloses a clamping mechanism for securing associated and encircling legs of a battery terminal about an upwardly, generally conically shaped battery post. More specifically, the present invention discloses an improved clamping mechanism for securing, in a tightened position, the terminal legs about the post in a regulated and non-destructive fashion, and which further provides for controlled spring-back of the terminal legs from about the battery post in a loosened position.
As also previously described, the ability to regulate the degree of clamping force exerted upon the terminal sleeve serves to assist in preventing plastic deformation of the sleeve (see again at 2) and, during loosening of the clamping mechanism, avoids the necessity of employing an additional tool (such as a screw driver or other pointed utensil) and in order to disengage the extending sides of the terminal post fitting from about the battery post. An additional advantage of the present invention is that it prevents undesirable damage to the battery post resulting from such over-torquing and clamping of the sleeve thereabout.
As described in the preceding description of the prior art, the conventional battery terminal includes a first end grippingly securing the terminal line. A substantially annual shaped post fitting is located proximate a second end of the battery terminal and included a pair of spaced apart guide walls communicable with the first and second spaced apart and extending legs, the first leg further including an upwardly extending and exteriorly threaded post.
The clamping mechanism includes a three dimensional and substantially elongated slider supported in laterally traversable fashion upon the first terminal leg. The slider includes a substantially elongated aperture defined therethrough and so that the slider is engaged through the terminal post and in seating fashion upon the plate (such as again at 18) further defining the second terminal leg. The slider is also fixedly engaged to an upwardly angled tab extending from a terminating edge of the second terminal leg (plate 16). The slider aperture further includes a pair of angling guides in the form of angled and recessed slots extending along opposing and inwardly facing sides of the aperture.
A nut assembly is threadably engaged over an extending end of the terminal post. The nut assembly includes a hex head, an intermediate an enlarged disk shaped portion and an extending and cylindrically shaped portion. A washer is secured in axially fixed and freely rotatable fashion to the cylindrical shaped portion. The washer further exhibits a pair of laterally extending wings seating, respectively, within said angled and recessed slots defined in the slider aperture.
In use, the nut assembly is rotated about the post so as to translate in first and second opposite directions and such that the inter-engaging guides actuate the slider between corresponding loosened and tightened positions. The slider is thereby laterally traversed in a controlled manner and with a controlled degree of clamping force being applied to the battery terminal, upon the second leg being forcibly drawn in a direction towards the first selected leg. Furthermore, a controlled spring back of the slider, to the loosened position, is accomplished upon the nut assembly being rotated in the second translating direction.